Electronic ignition and generator



Jan. 17, 1950 w. F. FAGEN ET Au.

ELECTRONIC IGNITION AND GENERATOR CONTROL APPARATUS Filed April 25, 1945Patented Jan. 17, 1950 ELECTRONIC IGNITION AND GENERATOR CONTROLAPPARATUS William F. Fagen, Indianapolis, Ind., and Charles W. Klug andArthur C. Allen, Chicago, Ill., assignors to Stewart-Warner Corporation,Chicago, Ill., a corporation of Virginia g Application April 23, 1945,Serial No. 589,806

(Cl. 29o-41) 8 Clalml.

The open air contact is subject, however, to very serious defects, themost prominent of which, of course, are actual mechanical wear, andoxidation due to the combined effects of heat and air. It has,therefore, seemed desirable to produce a 'system in which the excellentcharacteristics of the thermionic tube in respect to making and breakingcontact may be made use of. Among these characteristics are freedom fromvariation in qualities due to change in barometric pressure, longtrouble-free life with little or no deteriora` tion until the end-point,extreme reliability of operation, and perfect flexibility of control.

The existing automotive systems make use of the storage battery oraccumulator in conjunction with an electro-mechanical generatorconnected to the internal combustion engine by means suitable formaintaining the necessary power relationships for charging the battery.By virtue of the fact that thegenerator is mechanically connected to theinternal combustion engine a variable voltage is generated which must becontrolled by means calculated to limit the charging current. This meansmay, in the commonly used systems, consist of a simple compound wounddirect current generator, the series winding of which provides therising characteristic with load and the shunt of which is controlled byexternal means to produce the flat voltage characteristic, with respectto angular velocity of the mechanism. The external shunt field controlmeans most often consists of a system of contactors so arranged as toreduce the controlled field excitation as-the voltage generated acrossthe armature rises.

In the system of the present invention, this control is effected bymeans of a grid-controlled, gas-discharge tube so connected as to reducethe field excitation as the generated E. M. F. across the generatoramature rises with the angular velocity of the mechanism. This mayreadily be accomplished by providing a source of alternating voltagewhich is a .function of the generated continuous'or direct currentvoltage appearing across the generator brushes. Such an alternatingvoitage may easily be obtained from the conventional direct currentgenerator by connecting diametrically a pair of slip rings to thegenerator armature and taking the resultant E. M. F. from these sliprings. This alternating voltage will be very nearly inthe mathematicalratio of .'707 of the generated continuous voltage. The addition ofthese slip rings to the generating unit is a simple mechanical expedientwhich adds little to the cost of the machine. This alternating voltagemay then be increased by means of a suitable transformer.

It is apparent that in a system oi the foregoing type the frequency ofthe generated alternating current will be a' function of the angularrotative velocity of the machine. However, in the system of the presentinvention, variation in frequency may be eliminated as a problem incontrol of the field excitation, by means of suitable energystoringcapacitance.

$5 The generated alternating current voltage is vrectified to produce aproportional direct current control voltage which is utilized to controlthe generator field excitation to produce a generator output voltagehaving a flat characteristic with respect to the angular velocity of themachine.

Another feature of the system of the present invention is the vprovisionof electronic ignition pulse generating means energized from thealternating current supplied by the generator. This is accomplished bymeans including a simple rectifying system providing a source ofrelatively high continuous voltage which may be used with acold-cathode, grid-controlled, gas-discharge tube in association with acapacitance, charged through a relatively high resistance, and aconventional type of ignition coil, Initiation of the ignition pulse iseffected by a voltage source so connected to the timing mechanism as toproduce an instantaneous, highly-peaked pulse connected across the gridinput circuit. Means for producing this pulse preferably includes asimple ratchet arrangement having a number of teeth corresponding to thenumber of cylinders in the associated internal-combustion engine and soconstructed as to give a change in position of anl element of a magneticcircuit, independent of the rotative speed of the internal-combustionengine, at the desired time. The output of the ignition coil is suppliedto the rotor of the conventional distributor.

The present invention contemplates the proy duction of ignition impulsesbefore the engine is actually running by means including a disconnectclutch between the generator and its driving pulley enabling thegenerator to voperate as a converter, energized from the battery, untilthe engine speeds up. When this occurs the generator is connected totheengine and maintains a charge in the storage battery in accordance withdesired and predetermined characteristics.

The system of the present invention provides. in addition, a source ofalternating current for general purposes at al1 timeswith the additionaladvantage of a high efliciency of conversion without the inherentdisadvantages of vibrating contacts. A whole new field is therefore openin the matter of automotive accessories, such as the radio, inductiondefrosters, electrical instrumentation, and heating equipment. It iseconomical,

more reliable, and more satisfactory than the existing types of systems.t In addition, the characteristics of the thermionic tubes are auch thatthe operation is not subject to the rapid deterioration after adjustmentthat is 'encountered with the existing mechanical systems.

An important 'application of the ignition system is in high-altitudeaircraft operation where the independence of the characteristics of thethermlonic tube from barometric pressure is of vital importance. yInthis connection it may be mentioned that the ignition contacts arereplaced after each flight in high-altitude ilying. Thetremendous-advantage of a system which is independent of altitude isthus apparent.

One of the primary objects of the present invention is the provision ofnew and improved voltage regulating and ignition apparatus for internalcombustion engines.

Another of the primary objects of the present invention is to provide anew and improved ignition and generator control system for internalcombustion engines, and more specifically, a control includingelectronic devices for controlling both the ignition'and generator.

4, novel generata;- included in the embodiment of theinvention-illustrated in l'ig. i.

The control systeme! the present invention is adapted particularly forinternal combustion engines of various and especially high altitudeaircraft where mechanical ignition and control devices yhave seriousdisadvantages. The control system inmain: anv ignition system Il; avoltage regulator I2; a generator I4, used also as a converter. andsupplying power to the ignition system and voltage regulator; adisconnect clutch II: a control switch Il, which may be the customaryignition switch: and a battery 2l.

The battery may be of any conventional type. One terminal is connectedto ground by conductor 22 and the other to one terminal of switch il byconductor 24. The other terminal of the switch is connected by conductor2l to the terminal 28 of the generator I l.

The generator Il is of novel construction in that it includes means forproducing an alternating current control voltage proportional to itsangular velocity, which voltage, in accordance with the primary featuresof the present invention is supplied to the ignition system it and thevoltage regulator system l2, of which the latter controls the directcurrent winding of the generator to give it the desirable "fiatcharacteristic."

The generator includes the customary high impedance shunt ileld Il, alow resistance series field t2, a commutator 24 connected to thearmature winding 3l (of the distributed type). One terminal of the shuntfield is connected to ground and the other to terminal .22. One terminalof the series field is connected to the previously referred to terminal2l and the other is connected by conductor to one of the generatorbrushes 4t, the other of which is connected to ground.

t0 The alternating current voltage is obtained from thef' armaturewinding Il, preferably by a pair of slip rings 42 connected todiametrically opposite points ofthe winding. This voltage isproportional to the angular velocity of the arma- A further object ofthe present invention is to 45 ture and is very nearly in themathematical ratio provide a new and improved internal combustion enginecontrol system comprising an alternating' current generator.

A still further object of the present invention is to provide a new andimproved internal combustion engine control system including a batteryand a converter, and more speciiicallya converter having both direct andalternating current windings, the latter of which is utilized forproducing a control voltage for imparting desired characteristics to thedirect current windings andl for supplying energy to the ignition means.

Another object of the present invention is to provide a new and improvedinternal combustion a0 engine ignition system of the electronic typehaving -means mechanically synchronized with the distributor forproducing sharp peaked con trol pulses to control the electronic means.

A further object of the present invention is the provision of a new andimproved generator for use with internal combustion engines.

Other objects and advantages of the present invention will becomeapparent from the ensuing description of an embodiment thereof, in the 7course of which reference is had to'the accompanying drawing, in whichFig. 1 is a diagrammatic representation of one embodiment of theinvention; and

Fig. 2 is a schematic circuit diagram of the of .707 of the continuousvoltage generated by the generator. 'Ihe slip rings can be added to aconventional generator and the n conn nections can be made both readilyand eco- 50 nomically.

55 that the excitation decreases as the angular velocity of thegenerator increases, the regulator being supplied with the generatoralternating current voltage. The regulator includes means u forrectifying the alternating current voltage to provide a direct currentcontrol voltage.

It is preferred that the alternating current voltage be stepped upbefore it is supplied to the rectiiler by suitable means, such as atransformer It. The alternating current control voltage is supplied tothe primary winding Il of the transformer by the conductors Il and ,I2connected to the slip rings 42. The secondary winding I4 is connected toconductors latter is grounded.

The voltage regulator is connected across the secondary winding of thetransformer by conductors Il and l2 and it is constructed and arrangedto provide a shunt field excitation whichItincludesthepreviouslyreferredtorcctiiier.

type. auch as automobiles, tanks I! and Il, of which the oi the copperoxide type, and grid-controlled.

Y gas discharge tubeiof the 2051 type or o! the M.

type) connected to operate as a voltage regulator. The control grid B6oi.' the tube is supplied with a negative continuous voltage, verynearly proportional to the generator alternating current voltage, by therectifier.`

The rectiner is connected to the junction of the voltage dividerresistors B8 and 10, of which the iormer is adjustable, and which areconnected across the secondary winding by the conductors Il and 82. Theother terminal or the rectiiler is connected to the grid 66 of the tubeand to the shunt ileld terminal 38 through the parallel connectedcapacitance 'I2 and grid leak re sister 14. the connection beingeiiected by conductor 15. The anode 18 or tube BI is connected toconductor 60 and the cathode 80 is connected to the conductor 18. Afilter condenser 82 is connected in parallel with the shunt fieldwinding to render the excitation of the shunt eld free .ci any frequencyvariation eiects.

The ignition system includes a cold cathode. grid controlled gasdischarge tubeS (as of the 631121 type) adapted to be renderedconductive in timed relation with the operation of the engine andcontrolling ignition pulse producing means. The pulse producing meansincludes a capacitance 92 and an ignition coil or transformer 94, havinga primary winding 86 in 'series with the tube and capacitance andthrough which the capacitance is discharged at timed intervals. Thesecondary winding 9,8 of the coil is connected across the distributorit! and the ground connection 58. The distributor may be of any desiredor conventional type audit has therefore not been illustrated in detail.

The capacitance 92 is connected to the anode i0! of tube 90 by conductor|04 and the cathode it! oi' the tube is connected to one terminal of theprimary winding 96 by conductor |08. The other terminal winding 9,8 isgrounded.

The ignition pulse producing means is supplied with energy from thegenerator I4, preferably, by means including a rectiiier tube ||0 (whichmay be, for instance, oi the GF4 or 80 type) and a filter capacitance||2 connected in series across the secondary winding 54 oi thetransformer lli. The capacitance 92 is charged through a relatively highvalue resistor I |4 connecting the anode end of the capacitance to thecathode oi' -the rectifier tube.

The ignition pulses are produced at timed intervals synchronized withdistributor operation by control voltage pulse producing means. Thelatter may take different forms. It may include a sharp peaked pulsevoltage producing pickup |20 connected by conductor |22 to the controlgrid |24 oi' tube 8l operated as by a ratchet wheel |26 rotated insynchronism with the distributor. Each time an ignition pulse is to beproduced, the ratchet wheel operates the pickup to apply a sharp peakedcontrol voltage to the grid, thereby to render the tube conductive toeilect the discharge of condenser 92 through the tube and the primarywinding of the ignition coil.

In order that ignition pulses be produced before the engine is actuallyrunning, the generator is disconnected from its driving pulley by thedisconnect clutch IB so that it may operate as a converter and supplyalternating current voltage to the ignition system. Under theseconditions, the direct current windings of the generator operate as amotor (obtaining energy from the battery) to rotate the armature.thereby to produce an alternating current voltage across the slip rings.

The disconnect clutch I8 is shown between the generator I4 and/thegenerator driving pulleys |30 and |32, which are interconnected by abelt |34. Thus it normally disconnects the generator from the engine butconnectsl the generator to the engine when the latter accelerates tosome suitable speed. l

The operation of the system as a whole will now be described. When theswitch I8 is open the apparatus is inoperative. vWhen the switch isclosed the battery supplies energy to the generator I4, which runs as a.converter to supply alternating current to the ignition system I0 andvoltage regulator |2 through the step-upy transformer I6. Thisalternating current is. of course, available for such other purposes asmay be desired. The disconnect clutch I6 is open so that the generatormay readily operate as a converter without driving any mechanical load.

When the internal combustion engine is started. as by closing aconventional starter switch, A .the ratchet l|26 operates the pickup toproduce control voltage pulses which are supplied to the control grid|24 of the tube 90, with the result that the capacitance 92, which ischarged by the alternating current output from the rectifier ignitiontransformer 94 to produce high voltage ignition pulses in timed relationwith the distrib- The alternating current voltage generated by f thegenerator is a fixed proportion of .the continuous voltage so that, asthe latter rises, the alternating voltage will also rise. However, asthe alternating voltage rises the negative bias applied to the grid 86of the voltage regulator tube 8l increases. As the negative biasincreases the average current passed by the tube decreases,

thereby to decrease the excitation of the shunt field winding 30. Thevoltage regulator circuit may be made to level ofi at any desiredcharging rate and may be designed to produce different excitationvoltages dependent upon the requirements of particulanv systems.Adjustment is effected by the adjustable resistor 68 whereby theregulator may be` adjusted, in effect, to an infinite number of controlpoints and the present apparatus is, in this respect also, superior tothe usual regulators which have but two or three control positions.

While but a single embodiment of the invention has been described indetail, it should be understood that the details thereof are not to becon strued as limitative of the invention, except in so far as set forthin the accompanying claims.

Having thus described our invention, what we clatim as new and desire tosecure by Letters Paten is:

1. An ignition and generator control system for use with an internalcombustion engine, including in combination, a generator having adilrect current exciting ataque 7 winding and means for producing analternating current voltage proportional to the direct current output ofthe generator. clutch means normally disconnecting the generator fromtheengine. a step-up transformer coupled to the alternating currentoutput oi' the generator. means coupled to the transformer for supplyingignition pulses to the engine, means coupled #Q1 the transformer forcontrolling the excitation of the direct current winding, meansconnecting the generator to a source of power during starting of theengine whereby the generator is operated as a converter to produce analternating current output whereby ignition pulses are supplied to theengine, and means including said clutch means for connecting thegenerator to the engine after the engine has started.

2. An ignition and generator control system for use with an internalcombustion engine, including in combination, a generator having a directcurrent exciting winding and means for producing an alternating currentvoltage porportional to the direct current output of the1 generator,clutch means normally disconnecting the generator from the engine, astep-up transformer coupled to the alternating current output of thegenerator, means coupled to the transformer for supplying ignitionpulses to the engine, voltage regulator means coupled `to thetransformer for controlling the excitation oi' the direct currentwinding, a battery, means connecting the generator to the batterywhereby the generator is operated as a converter to produce analternating current output whereby ignition pulses are supplied to theengine, and means including said mally disconneetinl the generator fromthe engine and adapted to connect it'to the engine.

clutch means for connecting the generator to the engine after the enginehas started, whereby the battery is charged under the control of thevoltage regulator during operation of the engine.

3. A control system as claimed in claim 2,

wherein said ignition and voltage regulatorv means are of the electronictype.

4. An ignition and generator control system for use with an internalcombustion engine, including in combination, a generator having a directcurrent exciting winding and means for producing an alternating currentvoltage propcrtional to thel direct'current output of the generator,clutch means normally disconnecting the generator from .the engine, astep-up transformer coupled to the alternating current output of thegenerator, means including rectifying means-coupled to the transformerand a grid controlled gas discharge tube coupled to the rectifying meansfor supplying ignition pulses to the engine, voltage regulator meansincluding a grid controlled gas discharge tube and rectifying meanscoupled to the transformer for controlling the excitation of the directcurrent winding, means connecting the generator to a source of powerduring starting of the engine whereby the generator is operated as aconverter to produce an alternating current output whereby ignitionpulses are supplied to the engine, and means including said clutch meansfor connecting the generator to the engine after the engine has started.

5. A control system for an internal combustion engine, including incombination, a generator adapted to be driven by the engine, meansnormeans for operating the generator as a motor and for producing anoutput voltage during the starting of the engine, and means energized bysaid output voltage for supplying ignition pulses to the'engine.

6. An internal combustion engine control sys'- tem, including incombination, a generator havlng direct and alternating-current voltageoutputs for supplying a battery and the engine ignition, respectively,said alternating current output being proportional to the angularvelocity ct the generator, means energized by said alternating currentoutput for supplying ignition pulses to the engine. and voltageregulator means ,energized by the alternating current output forcontrolling the direct current voltage output of the generator. V Y

7. An internal combustion engine control system, including incombination, a generator having direct and alternating current voltageoutputs for supplying a battery'and the engine ignition, respectively,means energized by said alternating current output for supplyingignition pulses to the engine, and voltage regulator means energized bysaid alternating current output for controlling the direct currentvoltage youtput o! the generator.

8.1 A control system for an internal combustion engine, including incombination, a dynamo electric machine including shunt and series iieldwindings, a uniformly distributed armature winding, a commutator andslip rings connected to armature winding, means for energizing saidseries and armature windings with direct current to operate said deviceas a motor and to produce an alternating current voltage across saidslip rings, means including electronic rectifying and pulse producingmeans for supplying ignition pulses to the engine, and means suppliedwith said alternating current voltage for controlling the excitation ofsaid shunt field winding.

WILLIAM F. FAGEN. CHARLES W. KLUG. ARTHUR C. ALLEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,234,676 Langner July 24, 19171,917,565 Williams July 11, 1933 1,924,462 Bconeld Aug. 29, 19331,941,076 Edwards Dec. 26, 1933 1,957,016 Loudon May 1, 1934 1,981,738McNeil Nov. 201934 1,998,104 Sole Apr. 16, 1935 2,021,396 William'1 Nov.19, 1935 2,100,076 Gilmore Nov. 23, 1937 2,140,349 Dawson Dec. 13, 19382,169,818 Scott Aug. 15, 1939 2,301,440 Nardone Nov. 10, 1942 2,319,835Williams May 25, 1943 2,338,906 Dausinger Jan. 11, 1944 2,353,527Touceda et al July 11, 1944 2,367,960

Partt Jan. 23, 1945

